The present invention relates to teat cups for animal milking equipment and, more particularly, to such teat cups enabling the application of treatment fluids to animal's teats and the teat cups, post milking.
Conventionally, milking equipment installed in a milking parlor comprises a milking point at each animal stall within the parlor. Each milking point includes a milking cluster of teat cups for connecting the equipment to the teats of an animal to be milked. In the case of cows, for example, each milking cluster has four teat cups. Each teat cup comprises a hollow shell supporting a flexible liner which has a barrel portion for engaging about a teat and, at its upper end, has a head portion with a mouth through which the teat is engaged with the barrel of the liner. At the opposite, discharge end of the teat cup, the liner communicates with a flexible, short milk tube connected to a, so called, clawpiece of the cluster where the milk extracted from the animals teats is collected and delivered, via a flexible, long milk tube, to the collection vessel of the equipment.
Upon commencement of milking, a vacuum is applied to the teat cups, via the long milk tube, the clawpiece and the short milk tubes, for the purposes of extracting milk from the teat cups. This vacuum also leaks between the barrel of the liner and the engaged teat and is applied to a void formed about the teat in the head of the liner in order to capture the cup on the teat. Milking is achieved by automatically and alternately applying vacuum and atmospheric pressure pulses to the space between the shell and the liner of each teat cup in order to flex the liner and stimulate discharge of milk from the engaged teat. It is customary to apply these pneumatic pulses either simultaneously to the teat cups of a cluster or alternately to pairs of the teat cups. The clawpiece includes a distributor for distributing the pneumatic pulses to the individual teat cups, via flexible pneumatic lines or tubes.
After milking of an animal is finished, the milking cluster at the milking point is withdrawn from the animal's teats (commonly referred to as “take-off”) such as by an automatic cluster remover and, in a cleansing cycle, the teat cups are flushed internally with disinfectant and water and are dried with compressed air preparatory to use on the next animal to be milked. Each teat cup may be fitted with one or more injection nozzles for injecting treatment fluids into the heads of the liners, as described in my copending international application published under the number WO2005/043986. The treatment fluid is fed to the injection nozzles via a distributor of the clawpiece and, upon take-off, the milking cluster is designed to enable the short milk tubes to fall away from the centreline of the cluster so that the teat cups are inverted and hang with their heads downwardly from the clawpiece. Flushing is performed with the teat cups in this inverted position. Consequently liquid can escape through the head portions of the teat cups. The short milk tubes are connected to the clawpiece via spigots which are designed to cause the short milk tubes to be shut off at the spigots when the teat cups fall into their inverted position, so as to avoid entry of treatment fluid into the clawpiece and downstream milk tubes, and consequent contamination of the harvested milk, when the teat cup is back flushed subsequent to the milking of an animal.
Finally, at the end of a milking period, during which several animals may be milked at each milking point, the teat cups of each milking cluster are subjected to disinfecting and washing by a so-called “jetter” ready for use at the next milking period. The jetter is connected to sources of liquid disinfectant detergents and rinsing water and vacuum is applied to the teat cups of a cluster to draw said liquid from the jetter, whilst the teat cups are disposed in an inverted position.